JP2011153007A - Document reading device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a document reading device having an ADF cover and an FB cover, controlling a stopper to appropriately escape in accordance with an opening situation of both covers even when an opening and closing sensor for them is shared. <P>SOLUTION: When an output signal of a cover opening and closing detection sensor indicates opening, the stopper needs to escape. First, the presence of documents in a paper feeding conveyance path is confirmed ((503), (504)). In accordance with the result, a content of an escaping process is changed. When the documents are present in the paper feeding conveyance path, it is considered that the FB cover is opened. Accordingly, the escaping process is repeated until the situation is changed (505). When the documents are not present in the paper feeding conveyance path, it is considered that the FB cover is not opened. Accordingly, the escaping process is conducted only once ((506) and (507)). Thus, even with a simple cover opening and closing detection sensor, it is appropriately determined which cover is opened, and a necessary escaping process is conducted. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a document reading apparatus that reads an image of a document. More specifically, a leading edge regulating member that can both read individual originals on a flat bed and automatically convey and read a large number of originals and regulates the leading edge position of a bundle of documents for automatic conveyance reading. The present invention relates to a document reading apparatus having an image forming apparatus and an image forming apparatus having the same.

  2. Description of the Related Art Conventionally, in an apparatus having a function of reading an image of a document such as a copying machine, a fax machine, a scanner, etc., an automatic document feeder (hereinafter referred to as “hereinafter referred to as an“ original document feeder ”) that places a large number of documents to be read and sequentially feeds them one by one. Some have ADF). In this type of apparatus, it is necessary to regulate the position of the leading end of a bundle of documents used for automatic document conveyance.

  For this reason, for example, Patent Document 1 includes a sensor that detects the leading edge of a document when the document is set on a document tray. When the sensor detects the leading edge of the newly set document, the stopper is protruded to regulate the leading edge position of the document. Alternatively, a load is applied by lowering the paper feed roller instead of the stopper, and the user is informed that the leading edge of the document has reached the correct position. There is also a device for protruding the stopper in advance.

  Such a stopper needs to be retracted at the start of conveyance. In addition, an ADF cover that opens the ADF region is usually provided for jamming of the ADF, and it is necessary to retract the stopper even when the ADF cover is opened. This is because if the stopper remains protruding when the ADF cover is opened, the stopper may damage the document already set on the document tray when the ADF cover is closed. Even when the ADF cover is closed without removing the original document that has been stopped in the middle of the ADF, the original document may be damaged.

  Furthermore, apart from automatic document conveyance, so-called placement photography is also common in which an individual document is placed on a flat bed and an image is read, and both can be read by a single device. Many. In such an apparatus, there is an FB cover that opens a flat bed separately from the ADF cover. For this reason, some sensors have a sensor that can detect the opening and closing of each cover independently. This is because the stopper needs to be retracted when the ADF cover is opened, but it is not necessary when the FB cover is opened.

JP-A-6-263290

  However, the above-described conventional document reading apparatus has the following problems. First, in the case of a device that detects a document set on a document tray and protrudes a stopper, it is difficult to reduce the size of the device. This is because a certain amount of time is required for the protrusion of the stopper, and it is necessary to increase the distance from the sensor detection position to the protrusion position of the stopper. On the other hand, it is possible to reduce the size to some extent if it is a device in which the stopper is projected in advance. However, even in that case, if the mechanism that automatically retracts and protrudes the stopper is a mechanical structure, a complicated mechanical mechanism is required and the number of parts is large, and as a result, the size has not been greatly reduced.

  If an electromagnetic solenoid is used, the retracting projection mechanism can be downsized. However, as described above, the stopper needs to be retracted when the ADF cover is opened in addition to when the conveyance is started, but not when the FB cover is opened. For this purpose, two cover detection sensors are required, which has been a cause of cost increase. The detection sensors of both covers can be shared, but in that case, it cannot be determined whether the opened cover is the ADF cover or the FB cover. For this reason, even when the FB cover is opened, control for retracting the stopper works.

  However, if the ADF cover is closed only by opening the FB cover, the stopper cannot be retracted only by pulling the electromagnetic solenoid. This is because the stopper needs to be evacuated even in conjunction with the start of conveyance, and is therefore connected to the drive system for conveyance. The fact that the ADF cover is closed means that automatic conveyance is possible, and this connection is not released. For this reason, even if the electromagnetic solenoid is pulled to retract the stopper when the FB cover is opened, the stopper cannot be retracted. As a result, there was a problem that the electromagnetic solenoid was continuously pulled. On the other hand, the stopper must be retracted whenever the ADF cover is opened as described above.

  The present invention has been made to solve the above-described problems of the prior art. That is, the problem is that even if both the ADF cover and the FB cover are provided and the open / close sensor is shared, appropriate stopper evacuation control is performed according to the open state of both covers. An object of the present invention is to provide an original reading apparatus and an image forming apparatus equipped with the original reading apparatus.

  In order to solve this problem, the document reading apparatus according to the present invention can open and close both the image reading unit having a reading position for automatic conveyance reading and a reading position for individual reading and the reading position of the image reading unit. A first cover that covers the document, a document tray mounted on the first cover, and a document that is mounted on the first cover and is closed from the document tray to the reading position for automatic conveyance reading of the image reading unit. An automatic document feeder, and the automatic document feeder is located in the middle of the conveyance path from the document tray to the reading position for automatic conveyance reading of the image reading unit. A transport roller for transporting a document, a document sensor for detecting the presence of a document on the transport path, a rotational drive source for the transport roller, a first drive transmission member connected to the rotational drive source, and a transport path that can be opened and closed The second cover is connected to the first drive transmission member when the second cover is closed, and is disengaged from the first drive transmission member when the second cover is open. A second drive transmission member; a stopper that takes two states: a protruding state that restricts the position of the leading edge of the document on the document tray when the second cover is closed; and a retracted state that is retracted from the protruding state. , A pickup member that is moved by receiving rotational driving from the second drive transmission member and takes a first position where the stopper is in a protruding state and a second position where the stopper is in a retracted state; a second drive transmission member and the pickup member Among the rotational drives from the second drive transmission member to the pickup member, the rotational drive in the direction moving from the second position to the first position is transmitted, and the rotational drive in the opposite direction is not transmitted. A one-way clutch, a first engagement portion provided on the pickup member, which moves with the movement of the pickup member, and can be engaged with the first engagement portion only when the pickup member is in the first position. In the state, both of the second engaging portion that fixes the pickup member in the first position, the solenoid that pulls out the second engaging portion from the first engaging portion when turned on, and the first cover and the second cover And an opening / closing sensor for determining whether at least one of the first cover and the second cover is open. When the opening / closing sensor detects opening, the pickup member is There is a save control unit that puts the stopper in a retracted state by setting the position to the 2 position. When the document sensor detects the document, the save control unit detects that the document sensor cannot detect or opens the document. The second engaging portion is continuously pulled out from the first engaging portion by the solenoid until the closing sensor detects closing, and if the original sensor does not detect the original, the solenoid is used only within a predetermined number of times. The second engaging portion is pulled out from the first engaging portion.

  In this document reading apparatus, when the open / close sensor detects opening, the retract control unit places the stopper in the retracted state. This is because the document is not damaged by the stopper when the cover is closed. Specifically, the stopper is retracted by moving the pickup member to the second position. Here, the contents of the control differ depending on the detection status of the document sensor. It depends on whether or not the document sensor detects the document. When the document sensor detects the document, there is a high possibility that the second cover is open. This is because the user intends to remove the document from the conveyance path. Therefore, it is necessary to keep the stopper in the retracted state so that the document is not damaged by the stopper. Therefore, the retracting control unit continues to pull out the second engagement portion from the first engagement portion by the solenoid until the document sensor no longer detects the document or the open / close sensor detects the close. Thereby, the fixing of the pickup member by the engagement between the second engagement portion and the first engagement portion is released. Further, since the second cover should be opened, the connection between the first drive transmission member and the second drive transmission member should be released. For this reason, the pickup member moves to the second position, and the stopper is released.

  On the other hand, when the document sensor does not detect the document, the possibility that the second cover is opened is low. On the contrary, there is a high possibility that the first cover is opened. For this reason, it is not necessary to consider the original on the conveyance path, but it is necessary to retract the stopper at least once to protect the original placed on the original tray. Therefore, the retracting control unit pulls out the second engagement portion from the first engagement portion by the solenoid only within a predetermined number of times. Thereby, even if the open / close sensor is as described above, stopper evacuation control is performed according to the open / close state of the first cover and the second cover.

  In the document reading apparatus of the present invention, the second cover is provided with a clutch that is positioned between the second drive transmission member and the one-way clutch and switches between a state in which the rotational drive is transmitted and a state in which the rotational drive is not transmitted. It is even better if the part puts the clutch in the non-transmission state prior to putting the stopper in the retracted state. By disengaging the clutch, even if the open cover is the first cover, that is, even if the second cover is closed, the pickup member can be made free from the second drive transmission member. For this reason, the stopper can be retracted by the control processing of the retract control unit.

  The document reading apparatus according to the present invention has a jam flag instruction unit that indicates the occurrence of a jam in the automatic document feeder, and the evacuation control unit detects whether the document sensor detects the document or the jam flag instruction unit generates a jam. In this case, the second engagement portion is continuously pulled out from the first engagement portion by the solenoid until the document sensor no longer detects the document or the open / close sensor detects the close, and the document sensor does not detect the document. In addition, when the jam flag indicating portion does not indicate the occurrence of the jam, the second engaging portion may be pulled out from the first engaging portion by the solenoid only within a predetermined number of times. As a result, the occurrence of the jam can be determined more reliably.

  The image forming apparatus of the present invention includes any of the above document reading devices and an image forming unit that forms an image read by the document reading device on a recording medium.

  According to the present invention, even when both of the ADF cover and the FB cover are provided and the open / close sensor is shared, an appropriate document stopper control according to the open state of both covers is performed. An apparatus and an image forming apparatus equipped with the apparatus are provided.

1 is an external view of an image forming apparatus according to an embodiment. 3 is a cross-sectional view of a document reading unit in the image forming apparatus according to the embodiment. FIG. 1 is an external view showing a state where an ADF cover is opened while an FB cover is closed in an image forming apparatus according to an embodiment. 1 is an external view showing a state in which an FB cover is opened while an ADF cover is closed in an image forming apparatus according to an embodiment. 1 is a diagram illustrating a cover open / close detection sensor of an image forming apparatus according to an embodiment. It is a figure which shows the condition of the cover opening / closing detection sensor in the state in which both FB cover and ADF cover are closed. It is a figure which shows the condition of the cover open / close detection sensor in the state in which the FB cover is closed and the ADF cover is open. It is a figure which shows the condition of the cover opening / closing detection sensor in the state in which the FB cover is opened and the ADF cover is closed. It is explanatory drawing of the drive mechanism incorporated in ADF. It is a figure explaining a motion of a pickup unit. 2 is a block diagram illustrating a configuration of a control system of the image forming apparatus according to the embodiment. FIG. 6 is a flowchart (No. 1) showing a control flow of the ADF of the image forming apparatus according to the embodiment. 6 is a flowchart (part 2) illustrating a control flow of the ADF of the image forming apparatus according to the embodiment. 12 is a flowchart (No. 3) illustrating a control flow of the ADF of the image forming apparatus according to the embodiment. 12 is a flowchart (No. 4) illustrating a control flow of the ADF of the image forming apparatus according to the embodiment. 12 is a flowchart (No. 5) showing a control flow of the ADF of the image forming apparatus according to the embodiment.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, the present invention is applied to a document reading portion in an image forming apparatus whose appearance is shown in FIG.

  In the image forming apparatus 1 of FIG. 1, a document reading device 2 is disposed in the upper part of the apparatus. An image forming unit 3 is disposed below the document reading device 2. The image forming unit 3 incorporates a known structure for forming an image with toner, such as a photosensitive drum. There is a gap between the image forming unit 3 and the document reading device 2, and the upper surface of the image forming unit 3 is a paper discharge tray 4. A paper feeding unit 5 is disposed further below the image forming unit 3. The image forming apparatus 1 as a whole forms an image on the paper discharge tray 4 by forming an image with the image forming section 3 on the paper supplied from the paper feeding section 5 based on the image data acquired from the original with the original reading apparatus 2. It is configured to discharge.

  A sectional view of the document reading device 2 in the image forming apparatus 1 is shown in FIG. As shown in FIG. 2, the document reading device 2 includes an ADF (Automatic Document Feeder) 10 and an image reading unit 11. The ADF 10 is a device that conveys originals one by one from a group of originals placed thereon for reading by the image reading unit 11. The image reading unit 11 is a part that acquires image data from a document.

  The ADF 10 includes a document placement table 100 on which the document group PS is placed. The document placing table 100 is arranged so as to be inclined so that the front side (left side in FIG. 2) of paper conveyance is slightly lowered. A stopper 122 is provided at the left end in the figure. The stopper 122 is a member for regulating the tip position of the document group PS placed on the document placement table 100. As will be described later, the stopper 122 is movable, and can take two states: a protruding state and a retracted state. The stopper 122 in FIG. 2 is in a protruding state, and is a state in which the position of the front end of the document group PS placed on the document placing table 100 is regulated. When the sheet is actually conveyed from the document table 100, the protrusion of the stopper 122 is released.

  The ADF 10 is also provided with separation conveyance rollers 101 and 102. The separation conveying rollers 101 and 102 are rollers for taking out the originals one by one from the original group PS placed on the original placement table 100. The ADF 10 is further provided with a paper feed conveyance path 104 that guides a document taken out from the document table 100 to a reading position. In the middle of the paper feed conveyance path 104, a separation sensor 103, an inclination correction sensor 121, and an inclination correction conveyance roller 105 are arranged.

  The separation sensor 103 and the inclination correction sensor 121 are sensors that detect the presence or absence of a sheet at the corresponding position on the sheet feeding conveyance path 104. Specifically, it detects that the leading edge or the trailing edge of the document taken out from the document table 100 has passed the position. The separation sensor 103 has a role of causing the control system to recognize that the conveyance of the document has started by detecting the leading edge of the document, and a function of starting taking out the next document by detecting the trailing edge of the document. The tilt correction sensor 121 has a role of performing tilt correction by the tilt correction conveyance roller 105 by detecting the leading edge of the document and a role of allowing the control system to recognize the size of the document by detecting the trailing edge of the document. The inclination correction conveyance roller 105 is a roller for temporarily stopping the leading edge of the conveyed sheet, correcting the inclination, and restarting conveyance.

  A guide plate 106 is provided at the tip of the paper feed conveyance path 104. The guide plate 106 is a member that presses the document toward the image reading unit 11. The position where the guide plate 106 presses the document is the reading position when the document is read using the ADF 10. The ADF 10 is further provided with a document discharge table 110 for placing a document that has been read and discharged. Therefore, the ADF 10 is provided with a document conveyance path 108 that guides the document from the location of the guide plate 106 to the document discharge table 110. A transport roller 107 and a paper discharge roller 109 are provided in the middle of the document transport path 108.

  The ADF 10 is also provided with a document return path 120 for duplex reading. The document return path 120 connects the position between the transport roller 107 and the paper discharge roller 109 in the document transport path 108 and the position between the separation sensor 103 and the tilt correction sensor 121 in the paper feed transport path 104. . Further, the ADF 10 is provided with a support shaft 131 for an ADF cover 123 described later.

  The image reading unit 11 includes a reading glass 112, an exposure lamp 113, mirrors 114 to 116, a lens 117, an image sensor 118, and an image processing unit 119. The reading glass 112 is disposed at a position where the document is pressed by the guide plate 106 of the ADF 10. When reading an original using the ADF 10, the mirror 114 is positioned directly below the reading glass 112. Further, an exposure lamp 113 is positioned so that light can be applied to the document pressed against the reading glass 112 by the guide plate 106. As a result, an image of the reflected light from the original is picked up by the image sensor 118 via the mirrors 114 to 116 and the lens 117. Thereby, the image processing unit 119 acquires the image data output from the image sensor 118.

  The image reading unit 11 is further provided with a flat bed 111. The flat bed 111 is a large-area glass plate on which an original unsuitable for reading by the ADF 10 such as a book-like original is placed.

  Returning to FIG. 1, the document reading apparatus 2 is provided with an ADF cover 123 and an FB (flat bed) cover 124. The ADF cover 123 is placed on the FB cover 124. Also, all of the configurations of the document reading apparatus 2 described in FIG. 2 that belong to the ADF 10 are mounted on the FB cover 124 or the ADF cover 123. The ADF cover 123 and the FB cover 124 are both openable and closable, and both are closed in FIG. The ADF cover 123 is a cover that opens and closes by rotational movement about a support shaft 131 parallel to the width direction of the document. The FB cover 124 is a cover that opens and closes by rotational movement about an axis orthogonal to the width direction of the document.

  FIG. 3 shows the external appearance of the ADF cover 123 with the FB cover 124 closed. In this state, the posture of the FB cover 124 is not different from the state shown in FIG. 1, but the ADF cover 123 is slightly rotated counterclockwise and inclined as compared with the posture in FIG. . In this state, among the configuration of the ADF 10 described with reference to FIG. 2, the paper feed conveyance path 104, the inclination correction conveyance roller 105, and the like are exposed. In this state, it is possible to perform jam paper removal work when a document jam occurs in the ADF 10.

  FIG. 4 shows the appearance of the FB cover 124 opened with the ADF cover 123 closed. In this state, the FB cover 124 and the ADF cover 123 are integrally rotated around the axis on the back side in the drawing as compared with the posture in FIG. 1 and opened upward. In this state, the reading glass 112 and the flat bed 111 are exposed in the configuration of the image reading unit 11 described in FIG. In this state, a document can be placed on the flat bed 111. This is because the ADF 10 is not used but the flatbed 111 is used instead to read the document (so-called “placement taking”). Note that both the ADF cover 123 and the FB cover 124 can be opened.

  In the configuration of the ADF 10 illustrated in FIG. 2, the separation conveyance rollers 101 and 102 and the stopper 122 are attached to the ADF cover 123. For this reason, when the ADF cover 123 is opened, these components move together with the ADF cover 123 from the position in FIG. 2 other than those described above are attached to the main body of the ADF 10 instead of the ADF cover 123. Accordingly, these components are located at the positions shown in FIG. 2 even when the ADF cover 123 is opened.

  In addition, a cover open / close detection sensor 125 shown in FIG. 5 is mounted on the ADF cover 123. The cover open / close detection sensor 125 includes a rotating member 126 and an optical sensor 127. The rotating member 126 is a member in which the light shielding portion 129 and the weight portion 130 are integrally formed on the rotating shaft 128. As shown in FIGS. 6 to 8, the cover open / close detection sensor 125 is provided near the upper end in the opened state and close to the back side in the front-rear direction, in the ADF cover 123.

  In the cover open / close detection sensor 125, the light shielding portion 129 is only in the case where both the ADF cover 123 and the FB cover 124 are closed due to the weight balance between the light shielding portion 129 and the weight portion 130, that is, only in the state of FIG. 1. Light reception by the optical sensor 127 is blocked. Even when either the ADF cover 123 or the FB cover 124 is opened, the weight balance between the light shielding portion 129 and the weight portion 130 is lost, and the light shielding portion 129 is detached from the optical sensor 127. The same applies when both the ADF cover 123 and the FB cover 124 are opened. That is, it is possible to know whether the ADF cover 123 and the FB cover 124 are in the state shown in FIG. 1 or in any state other than FIG. For example, this can be done by arranging the rotation shaft 128 obliquely with respect to both the opening / closing shaft of the FB cover 124 and the rotation shaft of the ADF cover 123.

  In addition to what has been described so far, the ADF 10 further includes a driving mechanism for rollers. FIG. 9 shows the drive mechanism as viewed from above. As shown in FIG. 9, the ADF 10 includes a motor M. The motor M is a drive source for the separation conveyance rollers 101 and 102 and the inclination correction conveyance roller 105 of those shown in FIG. The rotational drive by the motor M is transmitted to the gear 133 via the gear train 132. It is also transmitted to the electromagnetic clutch CL5. The electromagnetic clutch CL <b> 5 is located between the gear train 132 and the above-described inclination correction conveyance roller 105. As a result, the transmission of the driving force of the motor M to the inclination correction conveyance roller 105 can be interrupted.

  9 described so far (the motor M, the gear train 132, the gear 133, and the electromagnetic clutch CL5 are the inclination correction conveyance rollers 105) are attached to the main body of the ADF 10. That is, it does not move depending on the opening / closing of the ADF cover 123. Among those shown in FIG. 9, what will be described (gears 134, 135, 136, 137, 138, 139, electromagnetic clutch CL4, separation conveying rollers 101, 102, roller shafts 141, 142, one-way clutches CL1, CL2, CL3. The stopper claw 140, the stopper 122, the pickup unit member 143, the pickup unit holding release solenoid SL1, and the pickup unit holding arm 144) are attached to the ADF cover 123. That is, it moves by opening and closing the ADF cover 123.

  The ADF cover 123 is provided with gears 134 and 135 coaxially. An electromagnetic clutch CL4 is provided between the gear 134 and the gear 135. The gear 134 meshes with the gear 133 described above in FIG. 9, but this is limited to the case where the ADF cover 123 is closed. When the ADF cover 123 is opened, the gear 134 moves together with the ADF cover 123, so that the gear 133 and the gear 134 are disengaged.

  The ADF cover 123 is further provided with a gear 136. The gear 136 is in mesh with the gear 135. The meshing between the gear 135 and the gear 136 is a constant meshing that does not come off when the ADF cover 123 is opened and closed. The gear 136 is attached to the roller shaft 142 together with the separation conveyance roller 102. A gear 137 is disposed between the gear 136 and the separation conveyance roller 102. A one-way clutch CL <b> 2 is further disposed between the gear 137 and the separation conveyance roller 102.

  The ADF cover 123 is also provided with a gear 138 that meshes with the gear 137 and a gear 139 that meshes with the gear 138. The gear 139 is attached to the roller shaft 141 together with the separation conveyance roller 101. A one-way clutch CL3 is disposed between the gear 139 and the separation conveyance roller 101. Further, stopper claws 140 are attached to both ends of the roller shaft 141. The stopper claw 140 is provided so as to be rotatable with a certain amount of frictional force with respect to the roller shaft 141. The stopper claw 140 regulates the movement of the stopper 122.

  The ADF cover 123 is also provided with a pickup unit member 143. The pickup unit member 143 is a member for swinging the position of the separation conveyance roller 101 around the position of the roller shaft 142. Therefore, the pickup unit member 143 is provided so as to be rotatable around the position of the roller shaft 142, and the roller shaft 141 is provided on the pickup unit member 143. That is, the pickup unit member 143 and the roller shaft 141 are further movable members when viewed from the ADF cover 123. A one-way clutch CL1 is provided between the pickup unit member 143 and the gear 138.

  The ADF cover 123 is further provided with a pickup unit holding release solenoid SL1 and a pickup unit holding arm 144. The pickup unit holding arm 144 is provided so as to be swingable around a fulcrum 145. A holding claw 146 is provided at one end of the pickup unit holding arm 144, and the other end is connected to the pickup unit holding release solenoid SL1. The pickup unit holding arm 144 can be swung by turning on and off the pickup unit holding release solenoid SL1. By this swinging, the holding claw 146 can be switched between the state in which it enters the pickup unit member 143 and the state in which it does not.

  The movement and role of the pickup unit member 143 will be further described with reference to FIG. FIG. 10 is a view of the pickup unit member 143, the roller shafts 141 and 142, the separation conveying rollers 101 and 102, the stopper claw 140, and the stopper 122 in FIG. 9 as viewed from below in FIG. FIG. 10 shows two states, “up position” and “down position”. “Up position” is a state in which the separation conveying roller 101 is raised. The “lowering position” is a state where the separation conveying roller 101 is lowered. This movement is caused by the pickup unit member 143 rotating around the position of the roller shaft 142. Therefore, the position of the roller shaft 142 is the same between the “up position” and the “down position”.

  As can be seen from FIG. 10, the stopper 122 is rotatable around the fulcrum 147. Further, the stopper 122 has a protruding portion 148 and a held portion 149. The stopper 122 in FIG. 2 corresponds to the protruding portion 148 in FIG. The fulcrum 147 is not provided on the pickup unit member 143 but is fixed to the ADF cover 123. Therefore, the position of the fulcrum 147 is the same between the “up position” and the “down position”. It should be noted that the stopper 122 is lightly biased so as to be sideways as in the “down position” unless it receives a force from others.

  The ADF cover 123 is provided with a regulating member 150 that regulates the movement of the stopper claw 140. The position of the regulating member 150 is also the same in the “up position” and the “down position”. Further, a pickup position sensor 152 that detects whether or not the pickup unit member 143 is in the “upward position” is provided.

  Further, as is apparent from the “lowering position” diagram, a recess 151 is provided on the side surface of the pickup unit member 143. The recess 151 is a part for the holding claw 146 of the pickup unit holding arm 144 to enter. The holding claw 146 can enter the recess 151 when the pickup unit member 143 is in the “up position”. When the pickup unit holding release solenoid SL1 is turned off at the “up position”, the holding claw 146 enters the recess 151. When the pickup unit holding release solenoid SL1 is turned on, the holding claw 146 is pulled out from the recess 151.

  On the other hand, when the pickup unit member 143 is in the “lowering position”, the holding claw 146 cannot enter the recess 151 even if the pickup unit holding release solenoid SL1 is turned off. This is because the holding claw 146 hits a position other than the recess 151 on the side surface of the pickup unit member 143. However, when the pickup unit member 143 reaches the “upward position” in this state, the holding claw 146 enters the recess 151.

  In a state where the holding claw 146 is pulled out from the recess 151, the pickup unit member 143 basically tries to be in the “lowering position” by its own weight. This does not matter whether the ADF cover 123 or the FB cover 124 is opened or closed. However, when the driving force is transmitted from the motor M, the “upward position” can be obtained. On the other hand, in a state where the holding claw 146 has entered the recess 151, the pickup unit member 143 is held at the “up position”.

  In the “ascending position”, the stopper claw 140 is in contact with the regulating member 150. Since the roller shaft 141 rotates counterclockwise in FIG. 10 in the process from the “lowering position” to the “upward position”, the stopper pawl 140 is dragged by the rotation until the stopper claw 140 contacts the regulating member 150. This is because it rotates clockwise. For this reason, the stopper claw 140 pushes out the held portion 149 of the stopper 122, and for this reason, the protruding portion 148 of the stopper 122 faces downward in FIG. This is a state in which the stopper 122 protrudes. However, since the roller shaft 141 rotates clockwise in FIG. 10 when the document conveyance is performed, the stopper claw 140 is detached from the held portion 149 by being dragged, and the stopper 122 is temporarily retracted.

  On the other hand, in the “lowering position”, the stopper claw 140 is detached from the held portion 149. This is because the position of the restricting member 150 remains unchanged while the roller shaft 141 is at a low position. Therefore, the stopper 122 is in a free state, and the protruding portion 148 is oriented sideways in FIG. This is a state where the stopper 122 is retracted. That is, the upward and downward movements of the pickup unit member 143 are movements that cause the stopper 122 to protrude or lower.

  Next, the overall control system of the image forming apparatus 1 will be briefly described with reference to the block diagram of FIG. As shown in the block diagram of FIG. 11, this control system is configured around a control device 311. The control device 311 has a data writing unit, a CPU, and a RAM. A non-volatile memory 312, an operation unit 310, a data communication control unit 309, a data input / output unit 308, a display unit 314, and an image memory 313 are connected to the control device 311. The data input / output unit 308 is connected to the network 315, the USB port 316, and other external memory ports 317 and 318. The operation unit 310 and the display unit 314 are located on an obliquely upward surface on the front side of the document reading device 2 as can be seen from FIG.

  A control device 311 in FIG. 11 also controls the document reading device 2, the image forming unit 3, and the paper feeding unit 5. When the image forming apparatus 1 has the finisher unit 6, the finisher unit 6 is also controlled. The control device 311 can also communicate with an external telephone line via the facsimile unit 302 and the communication control unit 303.

  Next, the control for raising and lowering the pickup unit member 143 in the ADF 10 will be described with reference to the flowcharts of FIGS. This control is also executed by the control device 311 in FIG. FIG. 12 is a basic flow of the entire control.

(501)
In the flow of FIG. 12, first, the output signal of the cover open / close detection sensor 125 is checked. Thereby, as described above, it is determined whether the ADF cover 123 and the FB cover 124 are both closed or at least one of the covers is open. If it is open, the process proceeds to (502), and if it is closed, the process proceeds to (509).

(502)
When the output signal of the cover open / close detection sensor 125 is open (it is unknown which of the ADF cover 123 and the FB cover 124 is open), the output signal of the pickup position sensor 152 is checked. Thus, it is determined whether the pickup unit member 143 is currently in the “up position” or the “down position”. If it is in the “up position”, the process proceeds to (503), and if it is in the “down position”, the process proceeds to (508).

(503)
When the output signal of the cover open / close detection sensor 125 is open and the pickup unit member 143 is in the “upward position”, the jam occurrence flag in the memory of the control device 311 is checked. The jam occurrence flag is a flag indicating whether or not a jam has occurred in the ADF 10. If this flag does not indicate the occurrence of a jam, the process proceeds to (504). If the occurrence of a jam is not indicated, the process proceeds to (505).

(504)
When the occurrence of a jam is not indicated by the flag, the state of the paper sensor on the paper feed conveyance path 104 is checked. The sensors checked here are the separation sensor 103 and the inclination correction sensor 121. At this time, since at least one of the ADF cover 123 and the FB cover 124 is open (according to the determination in 501), the document should not be conveyed. Therefore, if any one of these sensors detects the presence of paper, the document is stopped halfway. In that case, even if the flag does not indicate a jam, it is necessary to treat it as a jam. Therefore, if there is a document, the process proceeds to (505) as in the case where a jam indicates a flag. If there is no document, it can be determined that there is no jamming or has been resolved, and the flow proceeds to (506).

(505)
If it is possible to determine that a jam has occurred by using a flag or a sensor, “Descent control (1)” in FIG. 13 is performed.

(506)
If it can be determined that there is no jamming by using either the flag or the sensor, the recent execution history of “Descent control (2)” in (507) is checked. The reason for checking here is that “down control (2)” has not been performed or has not been performed since the last time the state of the cover open / close detection sensor 125 changed from closed to open until now. Or. If the “down control (2)” has not been performed once, the process proceeds to (507), and if it has been performed even once, the process proceeds to (508). That is, the “lowering control (2)” is performed only once during the period from when the cover open / close detection sensor 125 is opened to when it is closed.

(507)
When the “down control (2)” has not been performed, the “down control (2)” shown in FIG. 14 is performed.

(508)
Even if neither the flag nor the sensor indicates a jam, if the “down control (2)” has been performed, the “stop” shown in FIG. 15 is performed. Also, “stop” is performed when the pickup unit member 143 is in the “down position” in the above (502).

(509)
When the output signal of the cover open / close detection sensor 125 is closed in the above (501), the output signal of the pickup position sensor 152 is checked as in the case of (502). Thus, it is determined whether the pickup unit member 143 is currently in the “up position” or the “down position”. If it is in the “up position”, the process proceeds to (510), and if it is in the “down position”, the process proceeds to (511).

(510)
When the output signal of the cover open / close detection sensor 125 is closed and the pickup unit member 143 is in the “upward position”, “stop” in FIG. 15 is performed as in the case of (508) described above.

(511)
When the output signal of the cover open / close detection sensor 125 is closed and the pickup unit member 143 is in the “down position”, the “up control” in FIG. 16 is performed.

  Next, “Descent control (1)” in FIG. 13 will be described. As described above, this control is performed when the output signal of the cover open / close detection sensor 125 is open, the pickup unit member 143 is in the “upward position”, and it can be determined that a jam has occurred by a flag or sensor. This control is basically processing for retracting the stopper 122. Since a jam has occurred in the ADF 10, there is a high possibility that the open cover is the ADF cover 123. If the stopper 122 remains protruding, the stopper 122 attacks the top of the document group PS placed on the document table 100 when the ADF cover 123 is closed after the jam is cleared.

(601)
In "down control (1)", first, the electromagnetic clutch CL4 (PickUp roller CL in the flow) is turned off. As a result, the part below the gear 135 in FIG. 9 is disconnected from the motor M. If the open cover is the ADF cover 123, the gear 133 and the gear 134 are disengaged from each other, so that the portion is separated from the motor M. Even if the open cover is not the ADF cover 123 but only the FB cover 124, the part is separated from the motor M by the electromagnetic clutch CL4.

(602 to 605)
Then, the pickup unit holding release solenoid SL1 (PickUp unit lowering SL in the flow) is turned on. Thereby, the holding claw 146 is pulled out from the recess 151. Then, since the pickup unit member 143 is in a free state, the pickup unit member 143 is in the “down position” by its own weight. At the same time, the stopper 122 is retracted. This is because the stopper claw 140 is detached from the held portion 149 as described with reference to FIG.

  Here, regarding the pickup unit holding release solenoid SL1 being turned on, the duty is reduced to 100% for only the first one second, and thereafter the duty is decreased (604), and is kept on for a total of 11 seconds. The reason why the pickup unit member 143 is turned on for 11 seconds is because it takes a certain time for the pickup unit member 143 to drop from the “up position” to the “down position”. This is because of sliding resistance of clutches and the like of each part. If it can be confirmed that the pickup unit member 143 is in the “down position”, the pickup unit holding release solenoid SL1 may be turned on without waiting for 11 seconds. Decreasing the duty during the ON is a measure against overheating of the pickup unit holding release solenoid SL1. If the pickup unit holding release solenoid SL1 itself is provided with a mechanism for overheating, the duty may be kept at 100%.

(606,607)
When the pickup unit member 143 reaches the “down position”, the pickup unit holding release solenoid SL1 is turned off. As a result, the holding claw 146 enters a state of entering the recess 151, but in this state, it cannot enter. After holding in this state for 1 second, the process returns to the main flow of FIG. When returning to the main flow, as long as the status of the apparatus does not change, (505) is reached again, and the "down control (1)" is repeated. The “lowering control (1)” continues until the output signal of the cover open / close detection sensor 125 changes to closed or until both the flag and the sensor change without jamming. This is because the open cover is likely to be the ADF cover 123 as long as it is determined that a jam has occurred by either the flag or the sensor, and the stopper 122 needs to be securely retracted.

  Next, “Descent control (2)” in FIG. 14 will be described. As described above, this control is performed when the output signal of the cover open / close detection sensor 125 is open, the pickup unit member 143 is in the “upward position”, and both the flag and the sensor indicate no jamming. Only once. In this situation, the open cover is likely the FB cover 124. Although no document is left on the paper feed conveyance path 104, there is a possibility that the document group PS is set on the document table 100. For this reason, it is necessary to retract the stopper 122 at least once. The control for that is “downward control (2)”.

(701)
In the “down control (2)”, the electromagnetic clutch CL4 (PickUp roller CL in the flow) is first turned off. As a result, the portion below the gear 135 in FIG. This point is the same as (601) of “Descent control (1)”.

(702, 703)
Then, the pickup unit holding release solenoid SL1 (PickUp unit lowering SL in the flow) is turned on for 1 second. As a result, the pickup unit member 143 is set to the “lowering position” and the stopper 122 is retracted at the same time.

(704)
Then, the pickup unit holding release solenoid SL1 is turned off. As a result, the holding claw 146 enters a state of entering the recess 151, but in this state, it cannot enter. Then, the process returns to the main flow of FIG. Note that the fact that the “lowering control (2)” has been performed is recorded as a history until the output signal of the cover open / close detection sensor 125 is closed. For this reason, even if (506) is reached again in the next main flow, it is determined that it has been executed and is not executed. Instead, the “stop” of (508) is performed.

  That is, the “down control (2)” is performed only once. For this reason, the pickup unit holding release solenoid SL1 is not kept on even though the ADF cover 123 remains closed. It should be noted that the number of executions of the “downward control (2)” may be a plurality of times (however, a predetermined number) instead of once. Further, the contents of “down control (1)” and “down control (2)” may be the same.

Next, “stop” in FIG. 15 will be described. “Stop” is executed in the following three cases.
-When the output signal of the cover open / close detection sensor 125 is open and the pickup unit member 143 is in the "down position"-Neither the flag nor the sensor indicates jam, and "down control (2)" has been performed In the case where the output signal of the cover open / close detection sensor 125 is closed and the pickup unit member 143 is in the “upward position”, the previous two of these three types have the pickup unit member 143 in the “downward position”. (508). On the other hand, the last one is a stop in a state where the pickup unit member 143 is in the “up position” (510). Although there is a slight difference in this respect, the content itself of FIG. 15 is the same. First, “stop” (508) in a state where the pickup unit member 143 is in the “lowering position” will be described.

(801)
In “stop”, the pickup unit holding release solenoid SL1 (PickUp unit lowering SL in the flow) is first turned off. As a result, the holding claw 146 can enter the recess 151. However, it cannot actually rush. This is because the pickup unit member 143 is in the “down position”.

(802, 803)
Then, the electromagnetic clutch CL4 (PickUp roller CL in the flow) is turned off. As a result, the portion below the gear 135 in FIG. Then, the motor M (ADF motor in the flow) is stopped. Then, the process returns to the main flow of FIG. As a result, the pickup unit member 143 is not driven by the motor M, and therefore remains stopped at the “down position”.

  Next, “stop” (510) in a state where the pickup unit member 143 is in the “upward position” will be described. As described above, the flow itself in FIG. 15 is the same as that in the “lowering position”. However, in the “rising position”, when the pickup unit holding release solenoid SL1 is turned off in (801), the holding claw 146 actually enters the recess 151. Therefore, the pickup unit member 143 is held at the “up position” by the pickup unit holding arm 144. This is the difference from the “down position”. (802) and (803) are the same as those in the “down position”.

  Next, “rising control” in FIG. 16 will be described. As described above, this control is performed when the output signal of the cover open / close detection sensor 125 is closed and the pickup unit member 143 is in the “down position”. That is, at the start of this control, the stopper 122 is in a retracted state. This control is basically processing for causing the stopper 122 to protrude. Since all the covers are closed, it is considered that there is no inconvenience such as jam. Therefore, it is necessary to regulate the tip position of the document group PS placed on the document placement table 100.

(901)
In the “rising control”, first, the pickup unit holding release solenoid SL1 (PickUp unit lowering SL in the flow) is turned off. As a result, the holding claw 146 enters a state of entering the recess 151, but cannot enter at this point. This is because the pickup unit member 143 is still in the “down position”.

(902)
Then, the electromagnetic clutch CL4 (PickUp roller CL in the flow) is turned on. As a result, the rotational drive of the motor M is transmitted to the portion below the gear 135 in FIG. At this time, since the ADF cover 123 is closed, the gear 133 and the gear 134 are engaged with each other. For this reason, there is no problem in transmitting the driving force to the portion.

(903)
Then, the motor M (ADF motor in the flow) is driven. Then, the driving force of the motor M is transmitted in the gear train 132 → the gear 133 → the gear 134 → the electromagnetic clutch CL4 → the gear 135 → the gear 136 → the roller shaft 142 → the gear 137. The rotation direction of each gear at this time is as shown by an arrow in FIG. For this reason, the one-way clutch CL1 is locked, and the pickup unit member 143 rotates counterclockwise around the roller shaft 142 in FIG. That is, it moves from the “down position” to the “up position”. At the same time, the stopper claw 140 pushes the held portion 149 and causes the protruding portion 148 to face downward. Thereby, the stopper 122 protrudes. When the concave portion 151 of the pickup unit member 143 comes to the front of the holding claw 146 by this movement, the holding claw 146 enters the concave portion 151 there. This state is an “ascending position”.

(904,905)
Here, a maximum value is set for the number of pulses for driving the motor M for (903). This maximum value is set with a certain margin in consideration of losses due to various clutches on the drive transmission path from the motor M to the pickup unit member 143. For this reason, a certain number of pulses still remain even when the holding claw 146 enters the recess 151. However, when the remaining number of pulses are output, the motor M is stopped.

(906)
At this point, the pickup unit member 143 should be in the “upward position”. However, due to the loss of each part described above, it may still not be in the “ascending position”. For this reason, it is decided to retry. The retry is to perform the processing from (901) to (905) again. However, the number of retries is limited to one. Therefore, first, it is determined whether or not a retry has been performed. If not implemented (Y), the process proceeds to (907), and if implemented (N), the process proceeds to (908).

(907)
If no retry has been performed, control is returned to the main flow of FIG. 12 after waiting for 1 second. Then, it is determined again as “closed” at (501), and reaches (509). Here, if it is at the “rising position”, it becomes “stop” in (510). This means that “rising control” has ended normally. Therefore, the retry is not performed wastefully. In this state, the ADF 10 is in a state in which an original can be automatically conveyed. If it has not reached the “ascending position”, the “ascending control” of FIG. 16 is performed again (511). This is a retry.

(908)
In (906) after the retry, since it is determined that the operation has been completed (N), the process proceeds to (908). Therefore, the output signal of the pickup position sensor 152 is checked. As a result, it can be determined whether or not the “upward position” has been reached. If it is in the “ascending position”, the process proceeds to (907) and ends normally. If it is not in the “ascending position”, the process proceeds to (909).

(909)
Even if you try again, it will not be in the “ascending position”, so there may be some abnormality. Therefore, the electromagnetic clutch CL4 is turned off and the process ends. In this case, the control device 311 recognizes the abnormal end, and displays a message to that effect on the display unit 314. The document cannot be automatically conveyed. As the user, “rising control” can be performed again by opening and closing either the ADF cover 123 or the FB cover 124 once. This is because the retry execution history is cleared once the output of the cover open / close detection sensor 125 is set to “open”. The allowable number of retries is not limited to one, but may be a predetermined number of times.

  As described in detail above, in the image forming apparatus according to the present embodiment, when the output signal of the cover open / close detection sensor 125 is opened and the stopper 122 needs to be retracted, first, the document on the paper feed conveyance path 104 is firstly read. The presence or absence is confirmed ((503), (504) in FIG. 12). Based on the result, the contents of the saving process are changed ((505) and (507) in FIG. 12). As a result, even with the simple cover open / close detection sensor 125, an appropriate determination is made as to which cover is open, and necessary evacuation processing is performed.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, the present invention can be applied not only to the image forming apparatus as shown in FIG. 1 but also to a fax machine or a scanner machine. Even in the case of an image forming apparatus, the image forming unit may use ink instead of toner. Further, the electromagnetic clutch CL4 in FIG. 9 is not absolutely necessary. Even if the gear 134 and the gear 135 are in a directly connected state without this, since (507) in FIG. 12 is performed only once (or a predetermined number of times), the pickup unit holding release solenoid SL1 is useless. It is because it is not continued to be pulled.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Original reading apparatus 3 Image forming part 10 ADF
11 Image Reading Unit 100 Document Placement Table 103 Separation Sensor (Document Sensor)
104 Feeding conveyance path 105 Tilt correction conveyance roller (conveyance roller)
111 Flatbed (reading position for individual reading)
112 Reading glass (reading position for automatic conveyance reading)
121 Tilt correction sensor (document sensor)
122 Stopper 123 ADF cover (second cover)
124 FB cover (first cover)
125 Cover open / close detection sensor 133 Gear (first drive transmission member)
134 Gear (second drive transmission member)
143 Pickup unit member 146 Pickup unit holding arm holding claw (second engaging portion)
151 Concave portion (first engaging portion)
311 Control device (evacuation control unit, jam flag instruction unit)
CL1 One-way clutch CL4 Electromagnetic clutch M Motor SL1 Pickup unit retention release solenoid

Claims (4)

An image reading unit having a reading position for automatic conveyance reading and a reading position for individual reading, a first cover that covers both reading positions of the image reading unit so as to be openable and closable, and a document mounted on the first cover A document having a tray and an automatic document conveying device that conveys a document from the document tray to the reading position for automatic conveyance reading of the image reading unit when the first cover is mounted on the first cover and is closed. In the reading device,
The automatic document feeder is
A conveyance path from the document tray to a reading position for automatic conveyance reading of the image reading unit;
A transport roller located in the middle of the transport path for transporting the document;
A document sensor for detecting the presence of a document on the transport path;
A rotational drive source for the conveying roller;
A first drive transmission member connected to the precursor rotation drive source;
A second cover that covers the transport path so as to be openable and closable;
The second cover includes
A second drive transmission member coupled to the first drive transmission member when the second cover is closed; and a second drive transmission member disengaged from the first drive transmission member when the second cover is open;
A stopper that takes two states: a protruding state that restricts the position of the leading edge of the document on the document tray while the second cover is closed; and a retracted state that is retracted from the protruding state; A pickup member that receives a rotational drive from the transmission member and moves to receive a first position in which the stopper is in a protruding state and a second position in which the stopper is in a retracted state;
It is arranged between the second drive transmission member and the pickup member, and transmits the rotational drive in the direction of moving from the second position to the first position among the rotational drive from the second drive transmission member to the pickup member. And a one-way clutch that does not transmit the reverse rotational drive,
A first engagement portion provided on the pickup member and moving with the movement of the pickup member;
A second engagement portion that can be engaged with the first engagement portion only when the pickup member is in the first position, and in the engaged state, fixes the pickup member in the first position;
A solenoid that pulls out the second engagement portion from the first engagement portion when turned on; a state in which both the first cover and the second cover are closed; and the first cover and the first cover An open / close sensor for determining whether at least one of the two covers is open,
When the open / close sensor detects opening, it has a retracting control unit that places the pickup member in the second position to place the stopper in a retracted state;
The evacuation control unit
When the document sensor detects a document, the solenoid engages the second engagement portion until the document sensor does not detect the document or the open / close sensor detects the closing. Keep pulling from
When the original sensor does not detect an original, the original reading device is characterized in that the second engaging portion is pulled out from the first engaging portion by the solenoid only within a predetermined number of times. . 2. The document reading apparatus according to claim 1, wherein the second cover includes
A clutch that is positioned between the second drive transmission member and the one-way clutch and that switches between a state of transmitting rotational driving and a state of not transmitting;
The document reading apparatus, wherein the retracting control unit sets the clutch in a non-transmitting state prior to placing the stopper in the retracted state. In the document reading device according to claim 1 or 2,
A jam flag indicating unit indicating occurrence of a jam in the automatic document feeder;
The evacuation control unit
When the document sensor detects a document or when the jam flag indicating section indicates the occurrence of a jam, the solenoid causes the document sensor to stop detecting a document or until the open / close sensor detects close. Continue to pull out the second engagement portion from the first engagement portion,
When the document sensor has not detected a document and the jam flag indicating unit does not indicate the occurrence of a jam, the second engagement unit is moved by the solenoid only within a predetermined number of times. A document reading device, wherein the document reading device is pulled out from the first engaging portion. An original reading apparatus according to any one of claims 1 to 3,
An image forming apparatus comprising: an image forming unit that forms an image read by the original reading device on a recording medium.

Images